The influence of wet limestone/gypsum processes flue gas desulfurization system on fine particles morphologies, element composition and flue gas temperature and humidity was analyzed, and the super-saturation degree of flue gas in condensational growth chamber was calculated. On the basis of this, the removal of fine particles from wet flue gas desulfurization(WFGD)system was investigated experimentally by coupling impinging streams with heterogeneous condensational growth technology, and the results were compared with those of ordinary horizontal type heterogeneous condensational growth chamber. It is shown that fine particles morphology and element composition are changed obviously via wet limestone/gypsum desulfurization system. The relative humidity of flue gas approaches saturation or even super-saturation at WFGD system outlet. Only adding a small amount of steam can form super-saturation environment required by nucleation condensation. Fine particles can be removed more effectively by adopting the coupled impinging streams and heterogeneous condensation technology. The impinging streams heterogeneous condensational growth chamber has better performance in removal particles than ordinary horizontal type heterogeneous condensational growth chamber, for example, when the addition amount of steam is 0. 04 kg/m3, the number concentration removal efficiency increases from 34. 1% to 66. 1%. Increasing flue gas speed leads to higher removal efficiency.